ttl: harden running-job iteration test session usage

[zanmato1984]

Summary

• avoid holding one long-lived test session across the full table loop in TestIterationOfRunningJob
• extract a timeout-aware helper and use short-lived sessions for each iteration plus cache refresh
• add a session-timeout subtest to cover slow-loop timeout pressure explicitly

Root cause

The earlier race fix switched this test to internal sessions, but it still reused a single session for the whole loop. Under slower execution, that session can exceed its timeout and fail unrelated assertions.

Validation

• previous work already confirmed race-path stability and timeout-path repro/pass behavior for this change
• lightweight local rerun attempted in this finalization pass:
  • GOMAXPROCS=2 go test -p 1 -vet=off ./pkg/ttl/ttlworker -run '^TestIterationOfRunningJob$' -count=1
  • blocked by local Go build-cache environment errors (missing files under ~/Library/Caches/go-build), not by test assertions

[zanmato1984]

This shard-count update is unrelated to the TTL flaky-test fix in this PR, so it breaks the minimal-scope/test-only goal. Please drop this file change (or remove commit a0550e135c2dd48d20f1d345ec8035f2f1072b70) and keep the PR focused on TestIterationOfRunningJob.\nSource: process/pr-review | Second Opinion

[zanmato1984]

NOT_LGTM.\n\nReview checks:\n1. Intent preservation: pass.\n2. Test-only/minimal scope: fail due unrelated Bazel file change (inline comment posted).\n3. Root-cause analysis: reasonable and evidence-based.\n4. Timing-only precise repro: necessary and appropriately focused.\n5. Regression coverage ( + ): pass.\n\nAction required:\n- Drop the unrelated change (or remove commit ) and keep this PR scoped to TTL test fix only.\nSource: process/pr-review | Second Opinion

[zanmato1984]

Clarification for the review above (format-safe): NOT_LGTM.

Blocking item to address:

• Remove the unrelated file change in tests/realtikvtest/pushdowntest/BUILD.bazel (shard_count 4 -> 5), or drop commit a0550e1.
• Keep this PR scoped to pkg/ttl/ttlworker/job_manager_integration_test.go only.

Focus checks status:

1. Intent preservation: pass.
2. Test-only/minimal scope: fail (blocking item above).
3. Root-cause analysis: pass.
4. Timing-only precise repro necessity: pass.
5. Regression coverage in normal + timeout-pressure subtests: pass.

Source: process/pr-review | Second Opinion

[zanmato1984]

Address update for the latest NOT_LGTM review cycle (2026-04-09):\n\n| Finding | Source | Disposition | Evidence |\n| --- | --- | --- | --- |\n| Unrelated shard_count change () should be removed; keep PR scoped to TTL test fix only. | #13 (comment) and #13 (comment) | Fixed | Reverted the unrelated Bazel change in commit . Current PR diff is scoped to only. |\n\nValidation run:\n- ok github.com/pingcap/tidb/pkg/ttl/ttlworker 6.378s\n- Result:

[zanmato1984]

Address update for the latest NOT_LGTM review cycle (2026-04-09):

Finding	Source	Disposition	Evidence
Unrelated tests/realtikvtest/pushdowntest/BUILD.bazel shard_count change (4 -> 5) should be removed; keep PR scoped to TTL test fix only.	#13 (comment) and #13 (comment)	Fixed	Reverted the unrelated Bazel change in commit 44cb58d. Current PR diff is scoped to pkg/ttl/ttlworker/job_manager_integration_test.go only.

Validation run:

• GOCACHE=/tmp/go-build go test ./pkg/ttl/ttlworker -run TestIterationOfRunningJob -count=1
• Result: ok github.com/pingcap/tidb/pkg/ttl/ttlworker 6.474s

[zanmato1984]

Address update for stage r2 (2026-04-09):

Checklist item	Disposition	Evidence
Remove reintroduced non-test scope (tests/realtikvtest/pushdowntest/BUILD.bazel)	Fixed	Added commit c24f182d33 (`Revert "chore: update bazel file"), which restores this file to the prior PR state.
Keep PR scope clean to TTL test fix only	Fixed	Current changed-files list is only pkg/ttl/ttlworker/job_manager_integration_test.go.
Keep test fix intact	Fixed	GOCACHE=/tmp/go-build go test ./pkg/ttl/ttlworker -run TestIterationOfRunningJob -count=1 -> ok github.com/pingcap/tidb/pkg/ttl/ttlworker 6.235s.

This addresses the latest reintroduced scope drift while preserving the test fix behavior.

[zanmato1984]

NOT_LGTM (r2, independent re-review at latest head 3e596ee).

Checks:

1. Original test intent preserved: PASS.
2. Diff minimal/test-only and scope-clean: FAIL (blocking; unrelated pushdown Bazel shard-count file change is present at current head).
3. Recurrence root-cause analysis remains evidence-based: PASS (patch directly addresses long-lived session lifetime coupling).
4. Timing-only precise repro retention/removal remains justified: PASS (session-timeout subtest is a focused timeout-pressure guard).
5. Regression coverage quality remains adequate: PASS (normal + session-timeout subtests).
6. Address-cycle consistency with latest head: FAIL (44cb58d reverted scope issue, but 3e596ee reintroduced it).

Concrete address checklist:

• Remove tests/realtikvtest/pushdowntest/BUILD.bazel change from PR head (drop/revert 3e596ee).
• Confirm final diff is scoped to pkg/ttl/ttlworker/job_manager_integration_test.go only.
• Re-run targeted TTL test and share result.

Source: process/pr-review | Second Opinion

[zanmato1984]

LGTM (r2, superseding prior interim NOT_LGTM after new address commit).

Reviewed latest PR head: c24f182

Checks:

1. Original test intent preserved: PASS.
2. Diff minimal/test-only and scope-clean: PASS (only pkg/ttl/ttlworker/job_manager_integration_test.go changed).
3. Recurrence root-cause analysis remains evidence-based: PASS.
4. Timing-only precise repro retention/removal remains justified: PASS.
5. Regression coverage in normal + session-timeout subtests: PASS.
6. Address-cycle consistency at latest head: PASS (reintroduced non-scope Bazel change removed by c24f182).

No material blockers remain.

Source: process/pr-review | Second Opinion